Drain system for auto-defrost refrigerator



Nov. 29, 1960 w. MOMURRY MORRISSEY, JR., ETAL 2,962,337

naamsvsmw FOR AUTO-DEFROST REFRIGERATOR Filed Oct. 10v 1957 INVENTOR.

WILLIAM M- MORRISSEY.J'R. JOHN W- PULASKI THEIR ATTORNEY n SYSTEM non An'ro-nnrnosr nnnnronnn'ron William McMurry Morrissey, Jr., and John William Pulaski, Louisville, Ky., assiguors to General Electric Company, a corporation of New York Filed Oct. 10, 1957, sin. No. 689,356

3 Claims. (Cl. 312-429 The present invention relates generally to refrigerator cabinets and is more particularly concerned with a'defrost water drain system for use in such a cabinet.

Refrigerators including automatically defrostable evaporators require some means for collecting the defrost water flowing from the evaporator during the defrost operation and for disposing of this water outside the cabinet. In order to transport the collected water from the compartment containing the evaporator to a point outside the refrigerated portions of the cabinet, the drain system must pass through the insulation which is normally provided in the walls of a household refrigerator. A satisfactory drain system must therefore be'vapor tight to prevent migration of moisture either from the system or from the interior of the compartment into the insulated space between the compartment and the outer shell of the refrigerator cabinet. It should also be so designed that it can be readily built into the cabinet during the manufacture thereof.

It is therefore a primary object of the present invention to provide a vapor tight defrost water drain system which is arranged to transport defrost water through the insulated space between the inner liner and outer shell of a refrigerator cabinet and which is so designed that it can easily be built into a refrigerator cabinet during the assembly thereof.

Another object of the present invention is to provide a drain assembly for a refrigerator cabinet including a drain tube adapted to be attached to the outer shell of the cabinet between the inner liner and the outer shell and vapor tight means for connecting the inlet end of the drain tube to water collect-ing means generally disposed within the compartment.

Further objects and advantages of the present invention will become apparent asthe following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In carrying out the objects of the present invention, there is provided a refrigerator including an outer shell, an inner liner spaced from the shell and defining a food storage compartment, and means for collecting defrost water dripping from a defrosting evaporator within the compartment. In order to dispose of the defrost water outside of the compartment, there is further provided a drain tube secured to the inner side of the shell and having an inlet extending inwardly from the shell into substantial engagement with the outer surface of the inner liner. A funnel disposed below the defrost water collecting means within the compartment receives defrost water from the collecting means and discharges that water into the inlet end of the drain tube through a tubular portion of the funnel extending through an aperture in the inner liner and into the inlet end of the drain tube. Preferably, also the inlet end of the drain tube is provided Witha puncturable flexible membrane whichseals the end of the drain'tube during assembly of the refrigerator cabinet and which when punctured to receive the tubular portion 2,962,337 Patented Nov. 29, 1960 ICE of the funnel at the time that the tubular portionis inserted through the aperture in the inner liner forms with the tubular portion a vapor tight seal further to prevent water'vapor from entering the insulation disposed between theinner liner and outer shell of the cabinet.

For a better understanding of the invention reference may be had to the accompanying drawing in which: i

Fig. 1 is a side view of a refrigerator cabinet partially in cross-section embodying the present invention; and v Fig. 2 is an enlarged cross-sectional view of a portion of the structure shown in Fig. 1.

With reference to Fig. 1 of the accompanying drawing, there is shown a preferred embodiment of the present invention as applied to a refrigerator comprising an outer shell 1 and an inner liner 2 spaced from the outer shell and forming a storage compartment 3. Insulation 4 generally fills the space between the outer shell 1 and the inner liner 2.. For the purpose of cooling the contents of the compartment 3 there is provided asloping or inclined evaporator 5 disposed adjacent the topof the compartment 3 which forms part of a refrigerating system including a condensing unit positioned in a unit compartment 5 at the bottom of the refrigerator cabinet. This condensing unit includes the usual compressor 7 and condenser 8. Also forming part of the illustrated cabinet is a separate freezer compartment 9 between the fresh food storage compartment 3 and the unit compartment 6. It is to be understood of course that an evaporator for cooling the freezer compartment 9 is also provided and that both that evaporator and the evaporator 5 are connected by means of suitable tubing (not shown) to the condensing unit positioned in the 'unit compartment 6.

During operation of the refrigerating system frost accumulates on the evaporator 5 and in order to maintain the maximum operating efficiency of the system, it is necessary periodically to remove this layer of frost. Various means are well known in the art for periodically raising the evaporator 5 to temperatures above freezing in order to melt the accumulated frost. During the defrost operation, the defrost water flows downward along the bottom surface of the inclined evaporator and is collected in a drip trough H which in the embodiment of the invention shown is suitably secured to the rear wall 12 of theinner liner beneath the lower edge of the evaporator 5.

In order to dispose of the defrost water collecting in the trough 11 outside of the compartment 3, there is provided in accordance with the present invention a drain assembly including a drain tube 14 disposed in the space between the outer shell 1 and the inner liner 2 and suitably secured to the inner surface of the outer shell 1 by means of suitable fastening devices 15. This drain tube 14 which is fastened to the outer shell adjacent the upper end thereof extends downwardly along the inner surface of the outer shell 1 and through the bottom wall 16 forming part of the insulated partition between the unit compartment 6 and the freezer compartment 9. The drain tube terminates above a drain pan 21 positioned in heat exchange relationship with the condenser 8 so that the defrost water-collecting in the drain pan will be evaporated by the warm condenser. A trap or reverse bend 20 at the lower end of the drain tube seals the tube and prevents moisture from the water evaporating in the drain pan from migrating upwardly through the tube and back into the compartment 3 where it would condense on the bottom of the drip trough 11 and drip onto the contents of the compartment 3.

The upper flared end portion 22 of the drain tube extends inwardly and upwardly from the outer shell 1 and towards the inner liner wall 3 and into direct contact with this wall as shown in Fig. 2. By forming this portion of the drain tube and preferably all of the drain tube of of the trough 11 and a tubular portion 26 extending through an aperture 27 provided in the wall 12 and into the flared portion 22 of the drain tube.

As means for preventing migration of moisture from within the drain system into the insulation 4 and to facilitate the assembly of the drain system, the inlet end 29 of the drain tube is provided with a puncturable membrane 29 which if made of a vinyl material or the like heat sealed or otherwise secured to the end 28. This membrane 29 serves the dual purposes of preventing the insulating material 4 from entering the drain tube during assembly of the refrigerator cabinet and, when punctured to receive the tubular portion 26 of the funnel 25,

. engaging closely the outer surfaces of the tubular portion to form a vapor barrier.

The advantages of the present invention will become vmore apparent from the consideration of the ease with which the drain system of the present invention may be incorporated into a refrigerator cabinet during the manu facture or assembly of the cabinet. Since the drain system or assembly comprises two separate portions, the first portion comprising the drain tube is initially mounted on the inner surface of the outer shell 1 by means of the fastening device 15 at the top of the drain tube and the lower end of the tube is passed through the wall 16 and suitably secured within the unit compartment 6.

Thereafter the insulation 4 is placed within the outer shell 1 and as the membrane 28 seals the inlet to the drain tube, insulating material is prevented from entering the drain tube during this operation. When the inner liner 2 is placed in position within the outer shell 1, the rear wall thereof comes into contact with the flared portion 22 of the drain tube, the aperture 27 being arranged to be in alignment with the tube end 28. Finally, insofar as the assembly operations are concerned with the drain assembly, the funnel 25 is mounted on the wall 12 by inserting the tubular portion 26 through the aperture 27 and at the same time puncturing the membrane 28. Preferably, a sharp instrument is employed for this purpose so that the resulting aperture will be of a minimum size and will closely engage the tubular portion 26. An instrument shaped somewhat like a sharpened lead pencil may conveniently be used and by forming the funnel member 25 of rubber or other resilient material this instrument may be directly inserted through the top of the funnel and into the tubular portion 26 so that its pointed end extends out beyond the end of the tubular portion 26. In this position, the puncturing instrument strikes the membrane first to form a small opening therein which expands only sufliciently to receive the tubular portion 28. After the funnel has been inserted completely into the aperture 27 the instrument is withdrawn. By this procedure, a vapor tight connection between the portion of the drain assembly disposed between the inner liner 2 and the outer shell 1 and the funnel is assured.

While there has been shown and described a particularembodiment of the present invention, it will be seen that the invention is not limited to the particular form and it is therefore intended by the appended claims to cover all modifications coming within the spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. In a refrigerator including an outer shell, an inner liner defining a food storage compartment, a drain trough supported Within said compartment on one wall of said liner for collecting defrost water; means for dispos= ing of said defrost water outside said compartment comprising a drain assembly including a drain tube generally disposed between said outer shall and said one wall of said liner and secured to said outer shell, said tube having a flared inlet end composed of resilient material extending inwardly and upwardly from said shell into engagement with said liner, a puncturable flexible membrane closing said flared inlet end, a funnel disposed in said compartment below said trough for receiving defrost water therefrom, said funnel having a tubular outlet portion extending through an aperture in said one wall of said liner and into the flared inlet end of said drain tube through an aperture formed by puncturing said membrane during insertion of said tubular outlet portion through said aperture.

2. In a refrigerator including an outer shell, an inner liner defining a food storage compartment, a drain trough supported within said compartment on one wall of said liner for collecting defrost water; means for disposing of said defrost water into a unit compartment below said storage compartment comprising a drain assembly including a drain tube generally disposed between said outer shell and said one wall of said liner and secured to said outer shell, said tube having its outlet end in the unit compartment and including a trap adjacent said outlet end, said tube having a flared inlet end composed of resilient material extending inwardly and upwardly from said shell into engagement with said liner, a punctu-rable flexible membrane closing said flared inlet end, a funnel disposed in said storage compartment below said trough for receiving defrost water therefrom, said funnel having a tubular outlet portion extending through an aperture in said one wall of said liner and into the flared inlet end of said drain tube through an aperture in said membrane, the edges of said aperture closely engaging said tubular portion.

3. In a refrigerator including an outer shell, an inner liner defining a food storage compartment spaced from said shell, insulation in said space, a drain trough supported on one wall of said liner for collecting defrost Water, said wall having an aperture therein below said trough, and a funnel for receiving defrost water from said trough and having an outlet portion adapted to be inserted through said aperture into said space between said shell and said liner; means for disposing of said defrost water from said funnel comprising a drain assembly including a drain tube generally disposed between said outer shell and said one wall of said liner and secured to said outer shell, said tube having a flared inlet end composed of resilient material and extending inwardly and upwardly from said shell into engagement with said liner around said aperture, a flexible membrane sealed to and closing said flared inlet'end to prevent insulation from entering said flared inlet end during assembly of said cabinet, said membrane being composed of a puncturable material whereby said funnel outlet portion can be inserted into the flared inlet end of said drain tube through an aperture punctured in said membrane as said funnel outlet portion is inserted into said aperture.

References Cited in the file of this patent UNITED STATES PATENTS 477,758 Huss June 28, 1892 2,211,113 Hall Aug. 13, 1940 2,592,394 Cochran Apr. 8, 1952 2,688,235 Schwenker Sept. 7, 1954 2,783,065 Martin Feb. 26, 1957 

